In this monograph Dr. Seckel reviews his observations on 1,339 cases of diphtheria in 3 groups: group I, local; group II, progressive, and group III, toxic and septic. The 875 cases in group I were characterized by spotty, insular or spreading membranes and the 269 cases in group II by 10 different types of condition in the throat. In group III the 195 cases are divided according to toxicity. There are a pretoxic type and types with first, second and third grade toxicity, as well as hypertoxic and mixed types (toxicity associated with various infections). Sixty-three of the patients had other infections, such as measles, pertussis and lobar pneumonia. Attention is called to the common association of hemorrhagic diathesis, herpes, eosinophilia and fever with the disease and statistics are given on the number of male and female patients and the various age groups. The greatest number of cases occurred in